The expanding use of cellular communications has quickly consumed the radio frequency spectrum allotted to cellular communications. In some instances the cellular spectrum is further limited because it is shared with other communication technologies, such as WiFi, television, and Bluetooth.
Cellular communications are typically transmitted through cellular base stations using 3 antennas with a 120 degree beam width. This translates to 3 beams available for use for each channel of the cellular spectrum, which may be markedly insufficient for the number of users. Cellular base stations which are adjacent to or include overlapping transmission range with a neighboring base station may further limit spectrum channels to prevent interference.
Cellular providers may use subscriber codes, such and an international mobile subscriber identity to identify devices and enable encoded transmissions, enabling two or more devices to utilize the same 120 degree beam. The encoding of transmissions may include frequency domain multiple access (FDMA), code division multiple access (CDMA), polarization division multiple access (PDMA), time division multiple access (TDMA), or the like. However, these methods of coding have a limited number of available access slots.
Geographically based services based on cellular triangulation are dependent on the beam width and tower density and may suffer inaccuracies due to the relatively large beam widths of current cellular arrays especially in areas of low tower density. Each base station may determine a range in a beam arc which is may include the device to be located, the overlap of the beam arcs correspond to the estimated location of the device. Since the beam width is 120 degrees the beam arc as close as a mile away from the base station may be immense, resulting in unusable location information.
Cellular base stations are traditionally large elevated antenna towers which provide general cellular service to a wide coverage area. These large coverage areas may have portions in which the user density is very high causing interference and/or structures, in which, cellular coverage is blocked.